Eton Pharmaceuticals, Inc.
Eton Pharmaceuticals, Inc. (ETON) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ETON · as of Sep 30, 2025
Ownership Breakdown
105
Institutional Holders
▲ 15 vs Q2
$398.05M
Total Inst. Value
▲ $154.76M vs Q2
27.39M
Shares Outstanding
freeFloat 76.68%
18.19M
13F Shares Held
▲ 1.12M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
ETON largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
OPALEYE MANAGEMENT INC. pharmaceutical preparations | 2.86M | 10.63% | 10.63% | $62.15B | Nov 14, 2025 | — held |
ECOR1 CAPITAL, LLC pharmaceutical preparations | 2.03M | 7.55% | 7.55% | $44.12B | Nov 14, 2025 | — held |
BLACKROCK, INC. pharmaceutical preparations | 1.70M | 6.34% | 6.34% | $37.04B | Nov 12, 2025 | ▲ 172.7K |
VANGUARD GROUP INC pharmaceutical preparations | 1.34M | 5.00% | 5.00% | $29.21B | Nov 7, 2025 | ▲ 31.9K |
NANTAHALA CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 1.18M | 4.37% | 4.37% | $25.55B | Nov 14, 2025 | — held |
MORGAN STANLEY pharmaceutical preparations | 586.0K | 2.18% | 2.18% | $12.73B | May 27, 2026 | ▲ 76.5K |
GEODE CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 574.0K | 2.13% | 2.13% | $12.48B | Nov 12, 2025 | ▼ 18.8K |
pharmaceutical preparations | 492.1K | 1.83% | 1.83% | $10.69B | May 15, 2026 | — held |
ROYAL BANK OF CANADA pharmaceutical preparations | 479.2K | 1.78% | 1.78% | $10.41B | Nov 14, 2025 | ▲ 474.1K |
WESTSIDE INVESTMENT MANAGEMENT, INC. pharmaceutical preparations | 472.5K | 1.76% | 1.76% | $10.27B | Nov 4, 2025 | ▼ 250 |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
23
Increased
+1.83M shares3
New Positions
first time holders17
Decreased
−713.2K shares0
Sold Out
fully exitedNet shares change (top 50)
+1.12M
+1.83M / −713.2K
Net new holders
+9
3 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
ETON insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
7
Buy transactions
14
Sell transactions
0.50
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
BRYNJELSEN SEAN President & CEO | May 28, 2026 | Sale | 119,852 | $31.88 | $3.82M | 833.8K | Form 4 ↗ |
BRYNJELSEN SEAN President & CEO | May 28, 2026 | Sale | 148 | $32.67 | $4.8K | 833.7K | Form 4 ↗ |
Krempa David Chief Business Officer | May 22, 2026 | Sale | 32,963 | $33.22 | $1.10M | 35.1K | Form 4 ↗ |
Krempa David Chief Business Officer | May 22, 2026 | Sale | 9,315 | $33.88 | $315.6K | 25.8K | Form 4 ↗ |
Krempa David Chief Business Officer | May 27, 2026 | Sale | 19,679 | $31.47 | $619.4K | 25.2K | Form 4 ↗ |
Krempa David Chief Business Officer | May 26, 2026 | Sale | 37,524 | $31.49 | $1.18M | 25.2K | Form 4 ↗ |
Krempa David Chief Business Officer | May 22, 2026 | Sale | 519 | $35.00 | $18.2K | 25.2K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Eton Pharmaceuticals, Inc. (ETON) is primarily owned by institutional investors, who hold approximately 66.4% of total shares outstanding. Company insiders own approximately 23.32%, while retail and public investors account for the remaining 10.27%.
The largest institutional shareholder of Eton Pharmaceuticals, Inc. is OPALEYE MANAGEMENT INC., holding approximately 2.86 million shares — equal to 10.63% of outstanding shares — as of September 30, 2025.
A total of 105 institutional investors currently hold ETON stock, with a combined institutional value of approximately $398,046,931 as of the most recent 13F filing period.
Frequently asked questions
ETON ownershipEton Pharmaceuticals, Inc. (ETON) is primarily owned by institutional investors, who hold approximately 66.4% of shares. The largest shareholder is OPALEYE MANAGEMENT INC. with a 10.63% stake. Company insiders hold 23.32%. Data sourced from SEC Form 13F as of September 30, 2025.